The known transport container, from which the invention proceeds (WO 2008/137883 A1), is intended and suitable for the transport of temperature-sensitive products, in particular products that are sensitive regarding temperature fluctuations in the interior. Such products are, for example, certain pharmaceuticals, donor organs, blood reserves, but also artworks, etc., which are sensitive to fluctuations in temperature.
The known transport container, from which the invention proceeds, has a box-shaped outer container produced from corrugated board, from corrugated plastic, where applicable also from metal or from a combination of such materials. Plastic twin-wall sheets or plastic multi-skin sheets in a thin-walled design are occasionally referred to in practice as corrugated plastic.
The box-shaped outer container has a bottom, four side walls and at least one lid. In a particular case, four individual lids are provided, each of the individual lids being pivotably hinged on one of the four side walls. However, box-shaped transport containers where only one single, complete lid is pivotably hinged on one of the four side walls are also known.
In order to keep the temperature in the interior of the container uniform for as long as possible, plate-shaped vacuum insulation panels are situated in the outer container arranged on the side walls covering the surface.
Vacuum insulation panels are known per se and are described in the prior art which provides the starting point for the present invention (WO 2008/137889 A1). All the information concerning vacuum insulation panels can be found in detail in the further prior art (WO 2004/104498 A2).
It is essential that thermal bridges do not exist between the interior of the box-shaped transport container, which serves for receiving the product to be transported, and the ambient atmosphere, consequently therefore basically the box-shaped outer container itself. This is why it is important to minimize the gaps between the vacuum insulation panels. This occurs, for example, as a result of matching the box-shaped outer container as precisely as possible to the outside dimensions of the vacuum insulation panels which are arranged on the side walls covering the surface.
In the case of the previously explained, known box-shaped transport container, all the plate-shaped vacuum insulation panels of the side walls are configured in a rectangular-shaped manner with planar edges and are arranged in a circumferential manner in the box-shaped outer container in each case abutting against one edge and freely protruding at the other edge. In the case of a cubic outer container, it is possible, as a result, to produce all of the plate-shaped vacuum insulation panels provided on the side walls with the same dimensions, that is to say to use practically only one size of vacuum insulation panel.
From a different prior art (EP 2 221 569 A1), it is known, having the same objective, to configure the plate-shaped vacuum insulation panels of the side walls in a rectangular-shaped manner, but with edges beveled and mitered to 45°, and to arrange them mitered and abutting against one another. Here too, the same result is obtained for a cubic outer container, namely the use of only one size of vacuum insulation panel for the entire outer container.
In general, it is also still possible to provide plate-shaped latent heat storage elements or latent heat storage elements that are developed in another manner inside the box-shaped outer container making it possible to keep the temperature uniform in the interior of the transport container over a very long time and where the outside temperatures fluctuate a great deal (see also WO 2008/137883 A1). There are the same options for the outer shape of the latent heat storage elements as for the previously explained plate-shaped vacuum insulation panels (see WO 2008/137883 A1 and EP 2 221 569 A1).
As is produced from the prior art already addressed above, a vacuum insulation panel regularly consists of an open-pore support core and a gas-tight covering, regularly produced from corresponding film material (high barrier films). Sometimes a drying substance or a substance for binding gas molecules is also situated in the open-pore support core. The support core of a vacuum insulation panel has to meet various demands (see Wikipedia “vacuum insulation panel”). There are various substances for the material of the support core, namely typically open-pore plastics materials, microfiber material, pyrogenic silica and perlite.
In general, a finished vacuum insulation panel has a large flat body with planar surfaces and an edge region which is configured more or less precise in form.
To produce a vacuum insulation panel, it is possible to work with a core material which has been pressed previously to provide the final form, that is to say to provide a block or to provide a mechanically stable panel (DE 10 2010 019 074 A1). Then, as a result of skilled folding and working-and-turning the high barrier film, a vacuum insulation panel can be achieved, the edges of which are planar and accordingly themselves form planar contact surfaces. Such a vacuum insulation panel can easily be used in an outer container because the gaps between the vacuum insulation panels can be kept small and thermal bridges are accordingly able to be efficiently reduced.
However, vacuum insulation panels are also produced with a bulk powder core or with a core produced from microfiber material which is also filled loosely into the interior of the high barrier film. Such a vacuum insulation panel is not brought into its final plate-shaped form until the core material has been filled in. The outer covering of such a vacuum insulation panel consists of high barrier films which are welded flatly to one another along their circumferential edges or are connected together in a flat manner in some other way (WO 2007/033836 A1). This is called a sealing edge. Regularly, in the case of a sealing edge, the circumferential edge of the vacuum insulation panel with the wide weld seam that extends there or with a correspondingly bonded edge strip is somewhat irregular. A sealing edge is, as regards the gap, therefore more difficult to seal than a planar edge of a vacuum insulation panel with a plate-shaped core.
Vacuum insulation panels with a plate-shaped core are clearly more expensive to produce than vacuum insulation panels with a bulk powder core or with a core produced from microfiber material. Consequently, there is a conflict of objective between the desire for good heat insulation, that is to say the efficient avoidance of thermal bridges, on the one hand, and the costs of a correspondingly efficient transport container on the other.
Apart from this, it is generally applicable in the case of transport containers of the type discussed that, with reference to the exterior volume, as large an interior volume as possible would be wanted for the transport of temperature-sensitive products. In particular, when used in air freight, a larger exterior volume immediately affects the freight costs. It would therefore be desirable to have the thickness of the necessary thermal insulation as small as possible.
Proceeding from the previously explained prior art, the problem underlying the teaching of the invention is to optimize the known transport container, from which the invention proceeds, as regards the thermal insulation both with consideration to a cost viewpoint and with consideration to the available interior volume in the case of predetermined exterior volumes.